The present invention relates to a resiliently flexible pipe connection, and in particular a flexible pipe coupling for interconnecting two pipes in a pressure-tight manner, of the type consisting of a tubular metal casing formed with a longitudinal gap, a tensioning screw device secured thereto for reducing the width of the longitudinal gap and a sealing sleeve of resiliently flexible material, arranged within the casing and having formed on both free ends thereof sealing lips of predetermined thickness extending radially inwardly with respect to the pipes.
Such mechanical pipe connections of the flexible couplings type are provided for connecting together smooth-ended pipes of any material. Moreover, the couplings can be adjusted in the factory so that they fit over pipes even when the pipes are of the maximum size permitted within their tolerance range. By means of the screw device the metal casing is tightened in the circumferential direction of the pipes. A reliable sealing effect is ensured by the sleeve with its sealing lips. The sleeve adapts itself to changing pressures within the pipe. To a certain extent also differences in the outside diameters of the pipes to be interconnected can be compensated for by the known pipe couplings. Thus, for example, in the case of pipes having a nominal diameter of 50 mm to 350 mm, differences of between 1.5 mm and 4 mm can be compensated for solely by the elasticity of the sealing lips together with the flexibility of the metal casing. In cases where there are larger differences in the outside diameters of the pipes, there is the disadvantage that such a compensation is no longer possible.
In the field of gas and water supply as well as in water discharge apparatus the joining together of existing old conduits with pipes of present day manufacture, which in some cases may be composed of different materials and have a greater or smaller diameter than the existing old pipe, using the resiliently flexible pipe connections described above is not possible in cases where this dimensional different exceeds several mm. A requirement to join tubular conduits of different outside diameter may also arise where the wall thickness of the conduit parts are different due to the conduit parts being designed to operate to different nominal pressures or due to the conduit parts being made of different materials having different strengths and therefore requiring different wall thickness to withstand a given pressure.
Up to the present, the solutions to these problems have involved a high consumption of time and material, using complicated and expensive apparatus. For example, caulked sleeves are used which fit over the larger pipe and are then connected in an expensive operation with the surface of the smaller tube by caulking. Furthermore, reducing flanges are known which are used by welding, gluing or clamping flanges of equal dimensions provided with different connecting pieces to the existing pipes. Finally, the joining together of pipes of different diameters is carried out in accordance with the state of the art with the aid of reducing pieces which provide a gradual transition from the larger pipe to the smaller pipe and the ends of which are secured in an expensive manner to the said pipes.
As regards the known devices and methods for interconnecting pipes of different diameters, the general criticism must therefore be made that they are disadvantageous in that they are expensive in themselves and/or to use.
An object of the invention is, to enable smooth-ended pipes having diameters which differ from each other by more than the allowable tolerance range to be joined together in a simple manner and to enable a resiliently flexible pipe connection to be provided which, because of its construction, is simple to operate, is reliable as regards pressure-tightness and has advantages in connection with handling on the construction site. Altogether, a favourable economic efficiency will thereby be obtained for the user.